Use of melatonin as an inhibitor of apoptotic process for cryopreservation of zebrafish (Danio rerio) embryos

This study investigated the use of melatonin to arrest the effects of apoptosis in vitrified zebrafish (D. rerio) embryos. Dechorionated embryos at 22-24 somite-stage were divided (n = 60/treatment) into a non-vitrified (Control Group, 0 M melatonin) and vitrified treatments with 0 M (T1), 1 µM (T2) and 1 mM of melatonin (T3). For vitrified treatments, a solution methanol/propylene glycol based was used and the embryos stored in -196 °C for a week. After thaw, survival rate, scanning electron microscopy, expression of anti (bcl-2) and pro-apoptotic (bax/caspase-3) genes, reactive oxygen species (ROS) formation and DNA fragmentation analyses were performed. No live embryos were obtained from vitrified treatments, observing a rapid degeneration immediately after thawing, with the vitelline layer rupture and leakage of its content, followed by breakdown of epithelial cells and melanisation of the tissue. Regarding the apoptotic process, T3 had the highest relative gene expression, for the three genes (P < 0.05) furthermore, T2 had similar expression of pro-apoptotic genes to CG (P < 0.05). ROS formation revealed that CG presented lower percentage of embryo surface area affected (3.80 ± 0.40%) (P < 0.05), in contrast, no differences were found among the other groups. T1 was most significantly (P < 0.05) damaged by DNA fragmentation. The vitrified groups with melatonin had similar damage levels of CG (P > 0.05). The inclusion of 1 µM of melatonin in the vitrifying solution, countered the effects of apoptotic process in post-thaw embryos, suggesting its utility in cryopreserving fish embryos.

Molecular Mechanisms of Notopterygii Rhizoma Et Radix for the Treatment of Arrhythmia Based on Network Pharmacology

Background Many experiments showed that Notopterygii Rhizoma Et Radix (NRR) can resist arrhythmia, but the mechanism of its action has not clear. Here, we investigated the possible mechanisms of NRR by network pharmacology and molecular docking and verified them experimentally. Methods Active componds and targets of NRR were retrieved by the Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database andAnalysis Platform, SymMap, and the Encyclopedia of Traditional Chinese Medicine (ETCM) databases. Arrhythmia-related targets were acquired from Comparative Toxicogenomics Database (CTD) and GeneCards databases. Overlapping targets of NRR associated with arrhythmia were acquired via Venn diagram. DAVID was applied for GO and KEGG pathway analyses. Cytoscape software and its plug-in were used for PPI network construction, module division and hub nodes screening. AutoDock Vina and qRT-PCR were carried out for validation. Results The 21 active compounds and 57 targets were obtained. Of these, coumarin was the predominant category including 15 components and 31 targets. The 5 key targets of NRR in treating arrhythmia, and these targets are involved in the apoptotic process, extrinsic apoptotic signaling pathway in absence of ligand, endopeptidase activity involved in apoptotic process by cytochrome c. The main pathways are p53 signaling pathway, Hepatitis B and Apoptosis. The results of molecular docking and qRT-PCR display good effect on hub node regulation in NRR treatment. Conclusion NRR plays an important role in anti-apoptotic mediated by modulating p53 signaling pathway, which may provide insight into future research and clinical applications in arrhythmia therapy.

MBNL1 Regulates the Expression and Alternative Splicing of Genes Enriched in Cell Adhesion and Apoptosis

Muscleblind Like Splicing Regulator 1 (MBNL1), one canonical RNA binding protein (RBP), plays important roles in the regulation of the alternative splicing (AS) on pre-mRNAs. MBNL1 has traditionally been considered involved in the pathogenesis of myotonic dystrophy. Recent researches point out that MBNL1 has an effect on cancer progress, but the underlying mechanisms are unclear. In this study, we obtained the regulated transcriptome profile of MBNL1 in HeLa cells by RNA-seq analysis. The results showed that the knockdown of MBNL1 promoted cell proliferation while inhibited apoptosis. We found 398 genes were differentially up-regulated and 277 down-regulated by MBNL1 knockdown (KD). The differentially expressed genes (DEGs) regulated by MBNL1-KD were enriched in the signal pathways of homophilic cell adhesion, apoptotic process, extracellular matrix organization and cell migration. Systematical AS analysis revealed 504 MBNL1-regulated AS events. The regulated alternative splicing genes (RASGs) were enriched in the signal pathways of apoptotic signaling pathway, positive regulation of apoptotic process, adherent junction, fatty acid elongation and DNA repair. In summary, our results demonstrate that the knockdown of MBNL1 have significant effects on cell proliferation and apoptosis by regulating the expression and alternative splicing of associated genes, illustrating the possible molecular mechanisms of MBNL1 in cancer pathogenesis and progression and other diseases.

Super-resolution microscopy reveals that Na+/K+-ATPase signaling protects against glucose-induced apoptosis by deactivating Bad

Activation of the apoptotic pathway is a major cause of progressive loss of function in chronic diseases such as neurodegenerative and diabetic kidney diseases. There is an unmet need for an anti-apoptotic drug that acts in the early stage of the apoptotic process. The multifunctional protein Na+,K+-ATPase has, in addition to its role as a transporter, a signaling function that is activated by its ligand, the cardiotonic steroid ouabain. Several lines of evidence suggest that sub-saturating concentrations of ouabain protect against apoptosis of renal epithelial cells, a common complication and major cause of death in diabetic patients. Here, we induced apoptosis in primary rat renal epithelial cells by exposing them to an elevated glucose concentration (20 mM) and visualized the early steps in the apoptotic process using super-resolution microscopy. Treatment with 10 nM ouabain interfered with the onset of the apoptotic process by inhibiting the activation of the BH3-only protein Bad and its translocation to mitochondria. This occurred before the pro-apoptotic protein Bax had been recruited to mitochondria. Two ouabain regulated and Akt activating Ca2+/calmodulin-dependent kinases were found to play an essential role in the ouabain anti-apoptotic effect. Our results set the stage for further exploration of ouabain as an anti-apoptotic drug in diabetic kidney disease as well as in other chronic diseases associated with excessive apoptosis.

Integrated Transcriptomic and Proteomic Analysis Reveals Up-Regulation of Apoptosis and Small Heat Shock Proteins in Lens of Rats Under Low Temperature

Cold cataract is the reversible opacification of the lens when the temperature decreases. However, we observed that when temperature of the rats’ lens was maintained at a lower temperature for a prolonged time, the opacification of lens was only partly reversible. To review the potential molecular mechanism of the irreversible part of opacification under cold stimulation, we applied comparative transcriptomic and proteomic analysis to systematically investigate the molecular changes that occurred in the lens capsules of rats under low temperature treatments. The RNA sequencing based transcriptomic analysis showed a significant up-regulation of genes related to the lens structure and development in the Hypothermia Group. Hub genes were small heat shock proteins (sHSPs). Besides the same findings as the transcriptomic results, the liquid chromatography-tandem mass spectrometry based proteomic analysis also revealed the up-regulation of the apoptotic process. To further analyze the regulatory mechanism in this process, we subsequently performed integrated analysis and identified the down-regulation of Notch3/Hes1 and PI3K/Akt/Xiap signaling axis. Our research revealed the activation of the apoptotic process in rats’ lens under cold stimulation, and the sHSP related heat shock response as a potential protective factor through our transcriptomic and proteomic data.

Fisetin Induced Cell Death in Human Ovarian Cancer Cell Lines via ZBP1 Mediated Necroptosis.

Background: Ovarian cancer leads to severe female mortality among all reproductive cancers. Fisetin, a natural flavonoid, exerts pharmacological characteristics on inhibiting cancer growth from various origins. Although multiple mechanisms involving in regulating cell death, there is still unclear if and how fisetin exhibits anti-cancer effect on ovarian cancer. The presented study aimed to evaluate cell apoptotic and necroptotic processes occurring in ovarian carcinoma (OC) cell lines induced by fisetin Methods: Cell growth was evaluated by MTT assay in both OC cell lines treated with or without fisetin. Annexin V/Propidium iodide staining followed by flow cytometry were used to characterize fisetin induced cell death. The apoptotic process was suppressed by z-VAD intervention then cell necroptosis was assessed by introducing ZBP1 knockdown OC cell lines coupled with fisetin intervention. The expression of necroptosis-related mediators and migration capability of respective cells were evaluated by western blotting and in vitro cell invasion assay. Result: Fisetin successfully reduced cell growth on both OC cell lines in a dose-dependent manner. Both apoptosis and necroptosis were induced by fisetin. Suppression on cell apoptotic process failed to enhance proliferation of fisetin treated cells. The induced cell death as well as robust expression of necroptotic markers RIP3 and MLKL were alleviated by knocking down the expression of ZBP1 protein in both OC cell lines.Conclusion: The present study demonstrated in vitro evidence supporting that both apoptosis and necroptosis were involved in fisetin induced OC cell death, while ZBP1 regulates necroptotic process via RIP3/MLKL pathway.